“I think you can call it a perfect week," said Dolgopolov. "I didn’t lose a set and beat Kei for the first time. The fans were really supporting me and I felt very welcome here.”

With his remarkable turn in form this week, the Ukrainian earns his third ATP World Tour singles title and his first since prevailing in Washington, D.C., in July 2012. He also picks up his first win against his Japanese opponent, having lost all five of their previous FedEx ATP Head2Head meetings in straight sets. Dolgopolov gains 250 Emirates ATP Rankings points and receives a cheque for $97,470.

Dolgopolov didn’t drop a set throughout the week and advanced through a challenging draw. He defeated second seed Pablo Cuevas in the second-round and fourth seed Pablo Carreno Busta in the semi-finals before taking out Nishikori. Dolgopolov also handed Nishikori his first to a player outside the Top 50 since 2014, ending a 50-match win streak.

Nishikori was seeking his 12th ATP World Tour singles title, but finishes the week as the first Asian-born player to reach the Argentina Open final. He receives 150 Emirates ATP Rankings points and a cheque for $51,335.

“I’m glad to be here in the final. Unfortunately I lost today, but Alex played better than me," said Nishikori. "I didn’t play badly, so hopefully I can keep up this level.”

Both players traded service holds in the opening set to force a tie-break, but Dolgopolov found another gear when it mattered most, cracking a forehand winner on his second set point to grab the early advantage. The Ukrainian grabbed the lone break of the match at 3-3 in the second set with a backhand return winner. He held his slight advantage the rest of the way, converting on his first match point to prevail in one hour and 40 minutes.